2-Dienylphenacyloxazolones and an intramolecular Diels-Alder approach to the A-B-C ring system of phenanthridone alkaloids

A general route to the A-B-C ring system of phenanthridone alkaloids is available by acylation of 2-oxa-zolone with a 2-butadienylbenzoic acid derivative, followed by an intramolecular Diels-Alder reaction and hydrolysis.

A general route to the A-B-C ring system of phenanthridone alkaloids is available by acylation of 2-oxazolone with a 2-butadienylbenzoic acid derivative, followed by an intramolecular Diels-Alder reaction and hydrolysis.